Czech Journal of Food Sciences, 2012 (vol. 30), issue 5
Volatile organic compounds as biomarkers of the freshness of poultry meat packaged in a modified atmosphere
Jana Tománková, Gabriela Bořilová, Iva Steinhauserová, Leo Gallas
Czech J. Food Sci., 2012, 30(5):395-403 | DOI: 10.17221/408/2011-CJFS 
The volatile organic compounds (VOCs) in the packing of chicken meat in a modified atmosphere was qualitatively and quantitatively evaluated. The total number of 72 samples of chicken hindquarters were stored under two different modified atmospheres (70% O2, 30% CO2, and 70% argon, 30% CO2) for 20 days. Analyses were performed on Days 0, 4, 8, 12, 16, and 20. VOCs in the headspace samples were detected and quantified by gas chromatography/mass spectrometry (GC/MS) every fourth day of storage. Pentamethylheptane, dimethylsulphide, dimethyl disulphide, dimethyl trisulphide, dimethyl tetrasulphide, hydrogen sulphide and...
Effect of enzymatic modification on chicken surimi
Jerzy STANGIERSKI, Ryszard REZLER, Hanna Maria BARANOWSKA, Stefan POLISZKO
Czech J. Food Sci., 2012, 30(5):404-411 | DOI: 10.17221/451/2011-CJFS
The impact of the addition and duration of protein modification with transglutaminase preparation of microbial origin (MTG) of a chicken surimi on its texture, rheological characteristics, water molecular dynamics, and water activity were assessed. Surimi samples were supplemented with 0.3 g/100 g MTG and incubated maximally for about 7 h at the temperature of 15°C. The greatest changes of the chicken surimi properties were observed during the initial period, i.e. during 3 h of proteins incubation with MTG. Surimi modification with transglutaminase increased the equilibrium water activity in comparison with the value obtained for the control sample....
Evaluation of the stability of whipped egg white
Dalma Radványi, Réka Juhász, Csaba Németh, Ágnes Suhajda, Csaba Balla, József Barta
Czech J. Food Sci., 2012, 30(5):412-420 | DOI: 10.17221/258/2011-CJFS
An investigation was made into the effects of various egg white products and sweeteners on the stability and organoleptic properties of egg white foams. 12 foam products were prepared from egg white and sweeteners. The egg white was produced in the following forms: raw liquid egg white, pasteurised liquid egg white, liquid egg white treated at 55°C for 24 h, and spray-dried egg white powder. Three different sweeteners were used: sucrose, fructose-glucose syrup, and fructo-oligosaccharide syrup. The storage stability, firmness, adhesiveness based on the texture profile analysis, and organoleptic properties of the foams were evaluated. The flow curves...
Cell viability of Bifidobacterium lactis strain in long-term storage butter assessed with the plate count and fluorescence techniques
Magdalena Olszewska, Bogusław Staniewski, Łucja Łaniewska-Trokenheim
Czech J. Food Sci., 2012, 30(5):421-428 | DOI: 10.17221/330/2011-CJFS
Great interest in functional products containing bacterial strains displaying health-promoting properties is expressed worldwide and is as a result connected with a demand for developing new probiotic-based products, especially those containing bifidobacteria. The Bifidobacterium strains play a key role in gastrointestinal homeostasis, providing many health-related attributes, but as fastidious microorganisms require specific conditions (e.g. anaerobic environment, neutral pH) to survive in the long-term at the needed level above 106 cfu/g. In consequence, not every food product guarantees optimal maintenance of Bifidobacterium...
Solvent retention capacity for different wheats and flours evaluation
Ivan Švec, Marie Hrušková, Jan Karas, Taťána Hofmanová
Czech J. Food Sci., 2012, 30(5):429-437 | DOI: 10.17221/386/2011-CJFS
The baking quality in the sets of both commercial and variety wheat samples (80 and 18 items) and wheat composite flour (standard and 25 blends) was evaluated in terms of the Solvent retention capacity method (AACC 56-11). Composites were prepared from a commercial fine wheat flour and commercial bio-wholemeal flour prepared by milling of common wheat, rye, oat, barleys and corn at substitution levels of 10, 20, 30, 40, and 50%. The commercial wheat quality testing ANOVA revealed the major effect of the sample tested form; the data measured for grain and flour proved to be correlated. Besides, the harvest year affected the baking quality to a greater...
Determination of fluoride in plant material using microwave induced oxygen combustion
Emanuel Šucman, Jiří Bednář
Czech J. Food Sci., 2012, 30(5):438-441 | DOI: 10.17221/480/2011-CJFS
Fluorine is essential in human and/or animal nutrition, thus it is important to know its concentration in a diet. One of the important sources of fluorine for humans is tea, containing relatively high amounts of this trace element. A method for fluoride determination in various kinds of tea using microwave supported sample preparation in a high pressure oxygen atmosphere followed by potentiometry with a fluoride ion-selective electrode were described. The parameters of the microwave device for such combustion procedure were checked and optimised in order to find settings ensuring complete sample combustion and/or absorption of the analyte in the absorption...
Effect of thickening agents on perceived viscosity and acidity of model beverages
Zdenka PANOVSKÁ, Alena VÁCHOVÁ, Jan POKORNÝ
Czech J. Food Sci., 2012, 30(5):442-445 | DOI: 10.17221/286/2011-CJFS
The effect of thickening agents - methyl cellulose, hydroxyethyl cellulose, sodium carboxymethyl cellulose, and xanthan gum - solutions on the sensory viscosity was investigated in the concentration range of 0-0.8%. The perceived viscosity was proportional to the logarithm of kinematic viscosity in the presence of citric and malic acids. The viscosity was inversely proportional to the acidity at the viscosity levels higher than 10 mm2/s. A liquid of high viscosity thus possess lower acidity than aqueous or low-viscosity solutions. No significant differences were found between the effects of different thickening agents.
Sorption and wetting properties of pectin edible films
Sabina Galus, Anna Turska, Andrzej Lenart
Czech J. Food Sci., 2012, 30(5):446-455 | DOI: 10.17221/444/2011-CJFS
The water vapour sorption kinetics and isotherms of pectin films prepared by the casting method were determined. The measurement of water vapour sorption kinetics was conducted using a saturated sodium chloride solution to obtain constant relative humidity of the environment (75.3%). The measurement was carried out at the temperature of 25°C over a 24 h period. The water vapour adsorption rate was the highest in the first hours of the process. The exponential equation fitted well the experimental data of water vapour adsorption with time. Glycerol concentration in the analysed films affected the increasing water vapour adsorption. The water vapour...
Modelling the rheological behaviour of enzyme clarified lime (Citrus aurantifolia L.) juice concentrate
Shringari Subramanyaiah MANJUNATHA, Pakalapati Srinivasa RAJU, Amrindar Singh BAWA
Czech J. Food Sci., 2012, 30(5):456-466 | DOI: 10.17221/257/2011-CJFS
The rheological behaviour of enzyme clarified Lime (Citrus aurontifolia L.) juice was studied as a function of the total soluble solid (TSS) content (7.3-55.7°Brix), corresponding water activity (aw) (0.985-0.831) at different temperatures (20-80oC) using co-axial controlled stress rheometer. The rheological parameter shear stress was measured up to the shear rate of 600 s-1. The investigation showed that the enzyme clarified lime juice and its concentrate behaved like a Newtonian fluid with the viscosity (η) being in the range 3.964 to 50.290 mPa s depending upon the concentration and temperature...
Influence of various rootstocks on the yield and grape composition of Sauvignon Blanc
Borut PULKO, Stanko VRŠIČ, Janez VALDHUBER
Czech J. Food Sci., 2012, 30(5):467-473 | DOI: 10.17221/347/2011-CJFS
This influence of various rootstocks on the yield and grape composition of Sauvignon Blanc was examined. The yield on rootstock 41B/72 was 1 kg/vine or more higher than on rootstocks SO4 cl. 31, Riparia cl. 1 and Kober 5BB. The vines grafted on the Börner rootstock gave the highest weight of 100 berries (241 g). The highest seed weight of 100 berries (6.9 g) was found on rootstock 196/17 Cl, while the lowest one was on the Riparia cl. 1 (5.6 g). There was a strong, positive correlation (r = 0.91) between the berry and seed weights of vines on rootstock 41B/72 (2003). The total acidity content and the relationship between tartaric and malic...
Changes in quality parameters of vodka filtered through activated charcoal
Lucie Siříšťová, Šárka Přinosilová, Kateřina Riddellová, Jana Hajšlová, Karel Melzoch
Czech J. Food Sci., 2012, 30(5):474-482 | DOI: 10.17221/361/2011-CJFS
The production technology of high-quality vodka used in Russia involves filtration through activated charcoal. To approach the quality of renowned Russian vodka, one prominent Czech spirit-producing company installed on its production premises a filtration device including a charcoal column, and launched test runs during which different filtration conditions were tested. Samples collected during the test runs were analysed by GC-FID and GC-MS with the aim to compare their composition; sensory analysis was an integral part of the evaluation. The results documented a positive effect of charcoal filtration on the quality of produced vodka, which was not...
Aspergillus parasiticus from wheat grain of Slovak origin and its toxigenic potency
Mária Dovičičová, Dana Tančinová, Roman Labuda, Michael Sulyok
Czech J. Food Sci., 2012, 30(5):483-487 | DOI: 10.17221/247/2011-CJFS
During the mycological investigation of the wheat grain originating in Poltár (Central Slovakia), an endogenous aspergillus producing aflatoxins was encountered. Morphology, physiology and extrolites indicated the species Aspergillus parasiticus Speare. The amounts of aflatoxins detected by Liquid Chromatography/Tandem Mass Spectrometry on a synthetic medium were: B1 15.7, G1 23.4, B2 0.52, G2 0.68, and M1 0.18 mg/l. Compared to other screened strains, the amount of B1 produced was 5.6 mg/l lower than in A. parvisclerotigenus NRRL 3251 and 0.5 and 3.15 mg/l higher than in A. nomius I and A. nomius II, respectively. The production of G1 was 22.25 and...